A soldier with an exemplary Army record who was refused British citizenship because of a speeding conviction has won a legal battle to have his case reconsidered.

Sapper Poloko Hiri, 33, who was born and brought up in Botswana, joined the Army in August 2008 and served as a military draughtsman and combat engineer until 2012, when he decided to leave 73 Armoured Engineer Squadron for a university degree in architectural technology.

In February 2012, Sapper Hiri - a member of the British Army Reserve - applied for naturalisation as he feared lengthy imprisonment if he returned to Botswana, whose penal code provides that a person in possession of the uniform of the armed forces of any foreign country shall be deemed a security threat.

His application was refused in May 2012 on the basis that the Home Secretary was not satisfied that he met the "good character" requirement for naturalisation because of a November 2011 speeding conviction which would not be spent until November 2016.

Sapper Hiri was given a £100 fine and five points on his licence after pleading guilty to exceeding a temporary 50mph speed limit on the M1 after leaving Ripon Barracks for his Easter leave.

He applied for the decision to be reconsidered, supported by a very favourable reference from his commanding officer, Major Plimmer, but the refusal was confirmed.

In the High Court in London today, Mrs Justice Lang said that the decision-making process was legally flawed and the Home Secretary should reconsider in accordance with the law.

The judge said that Sapper Hiri's application was supported by unusually strong evidence of his good character from Maj Plimmer to the effect that he was an "intelligent, motivated and hard working soldier" with an "exemplary" record of conduct in his four years in the British Army.

Maj Plimmer said: "His character has been put to the test on various military training exercises where his peers have had to depend on him in austere and challenging environments.

"To see that Sapper Hiri has been denied British citizenship for what is deemed as 'bad character' directly contradicts his performance as a serving soldier.

"I have spoken to him about his speeding fine and he regrets his actions and has paid his fine. However, it appears that one moment's act of misjudgment has defined and tarnished his otherwise good character.

"The offence was a foolish mistake but it is not a reflection of his character from my experience as his officer commanding."

Wing Commander Dr Hugh Milroy, chief executive officer of Veterans Aid, which campaigned on Sapper Hiri's behalf, told the court: "I cannot emphasise how unique it is for a veteran to have left service without receiving a single charge.

"Soldiers frequently get into trouble and are disciplined; it is what they do. However, Poloko served without any blemish whatsoever.

"If Poloko were good enough to carry a weapon for this country, then surely he is good enough to be a citizen."

The judge said that in deciding whether an applicant for naturalisation met the good character requirement, the Home Secretary must consider all aspects of the applicant's character.

"Plainly, criminal convictions are relevant to the assessment of character, but they are likely to vary greatly in significance, depending upon the nature of the offence and the length of time which has elapsed since its commission, as well as any pattern of repeat offending."

She added: "The defendant is entitled to adopt a policy on the way in which criminal convictions will normally be considered by her caseworkers, but it should not be applied mechanistically and inflexibly.

"There has to be a comprehensive assessment of each applicant's character, as an individual, which involves an exercise of judgment, not just ticking boxes on a form."

The judge said that the May 2012 decision by an official in the UKBA (UK Border Agency) indicated that the assessment of Sapper Hiri's character was based entirely upon the fact that he had an unspent conviction - there was no reference to any other aspect of his character and background.

"This was not an adequate assessment of the claimant's character, as required by law. No references were sought from his employer, or his personal referees, and there was no interview with the claimant."

And, it was apparent that the UKBA official who then reviewed the case did not properly weigh in the balance the strong countervailing evidence of good character against the fact of the conviction.